Prefab GUIDs changing in 2019 beta

We're having a strange issue with prefabs that have a PhotonView component seemingly having their GUID changed and causing missing references in various components/ScriptableObjects throughout the project.

hi @JohnTubeyes I have this issue with unity 2018.3.I upgraded PUN to version 2.9.In my project exist nine different folder in resource and into each folder are two prefabs with ("base", "level1_default")when photon instantiate a prefabs on network, GUID change.I think this issue just happening on editor.